The present invention relates generally to integrated circuit packaging and more specifically, to a semiconductor package assembly that includes a carrier frame for mounting a semiconductor die.
Semiconductor packages are generally constructed by mounting and electrically connecting a semiconductor die (which may contain any of a variety of electrical circuits and distributing connections) to a substrate. The substrate and semiconductor die are typically sealed by an encapsulant, to protect the semiconductor die and circuits from external environments such as dust, moisture and electrical and mechanical shock. A printed circuit board, circuit tape, circuit film or lead frame are generally used as the substrate.
Typical semiconductor packages are manufactured in a variety of ways. Recently, in order to meet demands for low weight, small and thin packages as well as simplicity of manufacture and assembly, circuit tape and similar thin structures having a high interconnect density are used as substrates. In the above-mentioned type of semiconductor package, since the substrate easily bends during the manufacturing process, most manufacturing processes are performed using a metal carrier frame is attached to the top surface of the substrate. The carrier frame is removed from the substrate after the completion of the manufacturing process.
However, the above-described conventional semiconductor package provides poor heat discharge, since the package is not provided with a heat sink. Recently, with a trend toward an increase in operating frequency of semiconductor dies, an inevitable increase in heat generation has occurred. Therefore, the above-described conventional semiconductor package is inappropriate for packaging semiconductor dies that generate high heat. If a high heat semiconductor die is packaged in the above described semiconductor package, warping can occur, resulting in cracking of the semiconductor die or separation of the semiconductor package from external electrical connections.
The above separation problem occurs when the semiconductor package is bent in its cross-section, that is, the substrate becomes concave or convex in shape. The result is that the semiconductor die cracks and/or the semiconductor package becomes disconnected external connections, due to a difference in the coefficient of thermal expansion among the elements of the semiconductor package and the absence of a means for preventing warping.
Therefore, it would be desirable to provide a semiconductor package having a thin profile and low weight that will not severely warp or crack the semiconductor die when heat is generated within the semiconductor package.
The above stated objectives are achieved in various assemblies and methods for packaging a semiconductor die that include a carrier frame within the completed semiconductor package assembly. The assemblies include a carrier frame, a substrate, a semiconductor die and an encapsulation. The carrier frame provides support for thin substrates during and after the manufacturing process and may further provide a heat sink after manufacture of the semiconductor package. The carrier frame defines an aperture through a center portion that is raised above the plane of the carrier frame for accommodating a semiconductor die underneath. The aperture may be covered by a header that is attached to the carrier frame after the semiconductor die is attached and wire bonded to the substrate.